Dirichlet's Box Principle/Also known as

From ProofWiki
Jump to navigation Jump to search

Dirichlet's Box Principle: Also known as

Dirichlet's Box Principle, in particular its corollary, is also commonly known as the Pigeonhole Principle or Pigeon-Hole Principle:

Suppose you have $n + 1$ pigeons, but have only $n$ holes for them to stay in.
By the Pigeonhole Principle, at least one of the holes houses $2$ pigeons.

It is also known as Dirichlet's Drawer Principle or Dirichlet's Shelf Principle.

Some sources give it as the Letterbox Principle or Letter-Box Principle.


Some sources call it Dirichlet's Principle, but there is more than one theorem named such.

Some sources give this as the Dirichlet Principle.


Sources